This invention relates generally to optical signal processing and, more specifically, to optical digital signal processing.
Current optical signal processing systems include input modulation that is analog. This discrete analog input is used to drive the input light source. Conventional systems use analog spatial light modulators (SLMs) and therefore the output is also analog. Further, the detector array is also analog,often with limited precision, and normally requires its output to be digitized via an analog-to-digital (A/D) converter. The precision of the digitized output is then limited to the number of bits of the A/D dynamic range (e.g. 12xcx9c16 bits). Accordingly, precision loss may occur during A/D conversion. On the other hand, conventional digital SLMs comprised of binary micromirrors require 65,536 (2{circumflex over ( )}16) mirrors to represent a sixteen bit number.
In accordance with the present invention, the disadvantages and problems associated with analog and binary digital SLMs have been substantially reduced or eliminated.
One aspect of the invention is a method for optical digital signal processing, that comprises configuring a plurality of binary mirrors to allow a subset of the binary mirrors to represent a range of values. The plurality of binary mirrors comprises adigital micromirror device. Light from a light source is received at the digital micromirror device. The intensity of the light is altered to represent one of the values based, at least in part, on the configuration of the subset of the binary mirrors. The altered light is transmitted from the digital micromirror device to a detector array.